满深1井碳酸盐岩地层自愈合水泥浆固井技术

Cementing Technology of a Self-Healing Cement Slurry in the Carbonate Formations in the Well Manshen 1

满深1井三开钻遇破碎性碳酸盐岩地层,井壁掉块严重,井径不规则,且目的层油气显示活跃,三开尾管固井时顶替效率低,压稳和防漏矛盾突出。为确保该井三开固井施工安全顺利,并保障固井质量,通过选用自愈合剂BCY-200S和与其配伍性好的水泥添加剂,形成了自愈合水泥浆,并针对下套管和固井时容易发生漏失的问题,在根据前期施工情况准确判断漏层位置的基础上,采用了正注反挤固井工艺。满深1井三开碳酸盐岩地层采用自愈合水泥浆和正注反挤固井工艺后,固井作业安全顺利,既封固了产层,后期作业中也未出现环空气窜现象。研究和实践表明,自愈合水泥石遇油气可自动修复微裂缝,达到封固产层的目的,可解决塔里木油田高压天然气井环空带压及层间窜流的问题。

During the drilling of the fractured carbonate formation in the third spud of Well Manshen 1,serious problems were encountered such as severe sloughing of the borehole wall,irregular hole diameters,active oil and gas shows of the target layer,low displacement efficiency during tri-liner cementing,and prominent contradiction between pressure stabilization and lost circulation control.In order to ensure the safe and smooth cementing operation of the third spud of the well and guarantee the cementing quality,a self-healing cement slurry was prepared by self-healing agent BCY-200S and cement additives with good compatibility with the agent.In addition,considering that lost circulation occurred easily when running casing and cementing,the“forward injection and reverse squeeze”technique was adopted on the basis of accurately determining the position of the leakage layer according to the previous construction situation.After the application of the self-healing cement slurry and the“forward injection and reverse squeeze”cementing technique to the carbonate formation in the third spud of Well Manshen 1,the cementing operation was safe and smooth.It not only sealed the pay zone but also avoided the annular channeling in the later operation.The research and practice demonstrated that the self-healing cement could automatically repair the microfractures after encountering oil and gas.In this way,they could achieve the goal of sealing the pay zone and solving the problems of annular pressure and interlayer cross-flow in the high-pressure natural gas wells of the Tarim Oilfield.